Generator Batteries

Q: Recently I attended a meeting with our State Fire Marshall Department. One item which became a HOT topic of discussion was the monthly Specific gravity testing of the battery used to start up the generator. The Federal Regulation states that the cap should be unscrewed and then tested. Batteries are now sealed. The Fire Marshall’s response was that you peal off the sticker then pry the caps off. This triggers all kinds of issues, from a safety issue for employees to warrantees on the batteries. There are 3 battery monitoring procedures. 1. The annunciator for the generator monitors Low Battery and Low Charge. 2. Weekly monitoring of the 30 min test. 3. Monthly Load Testing I contend that this should be enough to support the monthly checking “Specific Gravity” checking. How do you see this to be?

A: What you’re referring to are newer style batteries that are sealed, and access to the electrolyte is not available, or necessary. But it really doesn’t matter what you contend or what I contend… it only matters what the State Fire Marshall will allow. It appears that they insist on specific gravity tests (i.e. electrolyte levels) so that is what you must do. You make a good case that opening a sealed battery is dangerous and voids the warranty of the battery. But NFPA 110-1999 Annex section A-6-3.6 says the specific gravity in the batteries must be recorded on a weekly basis.

However, section 1-4 of the same document does say that nothing in the document is intended to prevent the use of systems of equivalent or superior quality. You make a good point that the newer style sealed batteries are better than the older style that have caps and access to the electrolyte levels. One could argue that they are better than the older style. But this must be approved by the AHJ, which in this case is the fire marshal. Present a written plan to the fire marshal’s office and see if they will approve your plan to use sealed lead-acid batteries. Make sure it identifies the hardship, both financial and safety risk to staff, in using the older style batteries.

If they do not approve your plan, then I see no other choice that you have to purchase lead-acid batteries that has access to test the electrolyte levels as required by the AHJ. They are the authority and if you want their approval, then you have to do what they say. It is their prerogative to interpret the standards the way they see fit.